Electric heater unit



Aug. 25, 1936. DOWINSKY ELECTRIC HEATER UNIT Original Filed May 23, 1934INVENTOR Jamaal fiowizz s ky BY wa/vu/n 1. Iii S ATTORNEY Patented Aug.25, 1936 UNITED STATES PATENT OFFICE Application May 23, 1934, SerialNo. 727,036 Renewed December 14, 1935 3 Claims.

This invention relates to the windings of electrical heater units, andparticularly to devices adapted to be used in the heating of smoothingirons.

One of the objects of the invention is to provide a thin, flat heatingelement, readily portable and of light weight, on which the iron may beplaced while receiving the desired thermal effeet, or which may be builtinto the iron as a component, integral part.

A further feature is in the provision of means to control the degree ofheat it is desired to impart selectively, by mechanically arranging theresistance coils into difierent groups of varying watts orvolt-amperage, all of which are in the same level plane.

Another purpose is to produce a heating element of unusual thinness,strength, durability and economical construction.

These desirable objects are attained by the novel construction,arrangement and combination of parts hereinafter described and shown inthe accompanying drawing, constituting a material part of thisdisclosure, and in which:

Figure 1 is a top plan view of an embodiment of the invention.

Figure 2 is a similar view of a modified form of the same.

Figure 3 is a sectional view taken on line 33 of Figure l.

The core-like, plate body I5, of the device may be any thin flatdielectric material, preferably mica, because it is non-absorbent tomoisture in the atmosphere, not affected by heat, nor does it readilycrack, crumble or disintegrate.

The plate 15 may be solid or laminated, its profile shaped in conformitywith its purpose, here shown as adapted for use in heating a smoothingiron, but obviously can be made of any desired configuration.

The plate l5, as shown in Figure 1, is provided. with apertures IB-l'lthrough which may pass securing means whereby it is properly anchored,the larger apertures ll also permitting the passage of steam, if it beused in connection with the iron.

In the opposite side edges of the plate, near its wider, heel portion,are a group of rectangular notches l8-l8 in its respective edges,uniformly spaced apart, the notches being substantially equal in widthto the spaces therebetween, beyond which are a lesser number of similar,but more widely spaced notches I9l9, and further out are another uniformseries of notches 20-20, while therebeyond, reaching almost to thepoint, is the final series 2 l-2l.

In the heel portion of the'plate l5, spaced inwardly from the notchesl8--l8' on both sides, are a corresponding series of square perforations5 3838', similar openings 3939' registering with the notches l9i9', andfurther towards the point is another series of perforations 40-40,corresponding to the notches 20.

Spaced laterally adjacent the larger aperture 10 IT, on each side, aresimilar perforations 4|4l arranged in arcuate formation, and at theirapex is a central longitudinal row 4|.

At the rear of the plate IS, in the right side thereof as shown, is anopening 22, while further 15 to the right is a second opening 23, andstill further to the right is a third opening 24, these several openingsbeing in alignment and adjacent the rear edge of the plate.

At the left hand side is an opening 25, while 20 to the right are twocontiguous openings, respectively 26 and 2?, these last named openingsregistering with the first of the series of openings 38; thereabove is asingle opening 28 registering with the sixth opening 38) of the outerrow of 5 perforations 38, while adjacent the right hand side of thecentral circular aperture 16 are a plurality of similar openings 29,arranged in a longitudinal row, intermediate the aperture I6, and smallopenings 29, is an opening 30, register- 30 ing with the third opening390 in the row 39, and rearward of the opening 30, in the plate I5, isanother opening 3|.

On the opposite side of the aperture l6 are a series of openings 32corresponding to the open- 35 ings 29, all of these several openingsbeing rectangular and of a size commensurate with their purpose, whichis to receive the resistance wire.

A fiat strip of wire of high electrical resistance material, having anend 42 for connection to a source of electrical energy, is passed downthrough the opening 22, up out of the opening 23, along the uppersurface of the plate l5, into the opening 24, and out at the firstperipheral notch of the series E8 on the right hand side, then 45 passedthrough the corresponding first perforation in the series 38, on theright hand side, and wound thereafter alternately up and down throughthe notches and perforations l8--38, I9-39, 2!l l@,2l4l, and 4!",returning on the opposite side in the same manner, finally threaded upthrough the opening 21 to constitute a tap end 43, thus constituting thefirst and longest coil in the series.

Passing down through the same opening 21 is another resistance wire,having an inner tap end 44 directed upwardly through the opening 26 andthe wire extending thence across the plate l5, through the secondopening in the row 38' and then wound alternately through the openings3838' to emerge through the opening 38 to form a tap end 45, this coilconstituting the second and shortest coil in the series.

In a similar manner another resistance wire having a tap end 46 ispassed down through the opening 38], then up through the opening 28 tothe first opening in the row 29, thereafter alternately up and downthrough the openings 29-39 to 39d, thence down through 36, bentrearwardly towards the heel, to pass up through 38 to the opposite sideof the plate, where it is passed alternately through the openings 32 and39' on the left hand side and continued through a part of the adjacentrows of openings 3939 to extend upward through the opening 400 to form atap end All, this winding constituting the third coil in the series. 7

Another resistance wire having a tap end 43 passes down through theopening 400, thereafter to be wound through the row of openings l@ l!lto the last one Mm in the series, from which it extends to form a tapend 59, constituting the fourth and last coil in the series.

It will be understood that the resistance wires may differ in theseveral coils in cross sectional area and, hence potential resistance tothe current passing through them, and it will also be understood thatcontact buttons, not shown, are provided at the paired taps 43-46, 4545,l'a'48, and single tap-49.

'A switch arm, not shown, pivoted at the point is connected with theother pole of the electric circuit and is capable, as indicated by theradial lines, of swinging in the arc of a circle to selectively engagethe tap buttons whereby any of the several resistance coils may beplaced in circuit.

For instance, in the device shown in Figure 1, when the shortestcircuit, between the switch arm and tap end 56 is completed,approximately 660 watts is obtained; when the switch arm is moved toengage the tap'e'nd 46, the wattage is decreased to 530 watts; when incontact with the tap end 41 there is a further decrease to 400 watts;and when engaged with the single tap 59, the lowest degree of heat 280watts is imparted, this, the longest circuit, enclosing within itsinterior profile all of the several shorter circuits in the mannerindicated.

The windings of the resistance wire as seen in Figure 2, are of asimilar type, the heating capacity being controlled by a switch armcentered at 60 and operative to engaged taps til-62; 6364; i566; and 61,current passing from the switch arm centered at 68, to the various tapsand entering at the terminal 69.

Having thus described the invention and set forth the manner of theconstruction and operationof its best known embodiments, what is claimedas new and sought to secure by Letters Patent, is:

1. A heating unit comprising a dielectric plate having spaced notches inits marginal edge and having spaced perforations therein. alined withand spaced inwardly from said notches respectively, a resistance wirepassed around said plate and extending in said notches and perforationsto form a helix overlying that portion of the plate between theperforations and the edge of the plate, and a second resistance wirepassed around said plate and extending in said perforations to formanother helix overlying that portion of the plate between theperforations, said helixes being electrically connected to each otherand being of different current capacities. a v

2. A heating unit comprising a dielectric plate, a resistance wireengaged with said plate to provide a 'flat helix extending aboutopposite side marginal portions of the plate, and a second re sistancewire engaged. with said plate to provide another fiat helix extendingabout the plate between said first helix, one terminal of one helixbeing connected with one terminal of the other helix, and said helixesbeing of different lengths.

3. A heating unit comprising a dielectric plate having spaced notches inits edge at opposite sides thereof, and also having spaced perforationstherein spaced inwardly from said notches, said perforations beingarranged in groups offset with respect to each other, a resistance wirepassed around said plate and extending in said notches and perforationsto form a helix overlying that portion. of the plate between theperforations and the edge of the plate at opposite sidesthereof, andadditional resistance wires passed around said plate and extending insaid perforations to form additional helixes overlying that portion ofthe plate between the perforations, said helixes being electricallyconnectedto each other in series, and certain terminals of said helixesprojecting upwardly through certain of saidperforations.

SAMUEL DOWINSKY.

